Systematic monitoring of the conversion of pedunculate oak (Quercus robur L.) and sessile oak (Quercus petraea L.) seedlings with regard to different planting methods

Istraživanja su obavljena u nizinskom dijelu Varaždinske županije, u šumi posebne namjene „FOPER“, g. j. „Zelendvor odsjek 13c na oko 3 km udaljenosti od rijeke Drave na nadmorskoj visini od 190 m, u području gdje su sađene pretežito kulture smreke, borovca i bagrema iako je stanište pogodno za sadnju i uzgoj hrasta. S obzirom na promijenjene ekološke i klimatološke prilike osnovana je 2012. godine trajna pokusna ploha veličine 2,00 ha. Na plohi su posađene trogodišnje (2 + 1) sadnice hrasta lužnjaka (Quercus robur L.) i hrasta kitnjaka (Quercus petraea L.) i to na dva načina. Jedan dio u razmaku sadnje 3 x 3 m u polipropilenskim štitnicima. Drugi dio razmaka sadnje 2 x 2 m uobičajenim načinom (bez štitnika). Cijela je površina podijeljena na 24 pod plohe približnih površina. Na jednoj plohi nalazi se jedna vrsta drveća. Raspored vrsta je naizmjeničan od plohe do plohe. Upotrijebljen je randomizirani oblik metode, sa 4 bloka i 3 ponavljanja. Visine biljaka mjerene su 5 godina uzastopce za vrijeme mirovanja vegetacije. Prsni promjeri mjereni su na kraju promatranog razdoblja kada su biljke bile više od 1,30 m. Učešće i intenzitet pepelnice utvrđivan je tri godine tijekom ljetnih mjeseci. Cilj istraživanja je proučavanje rasta i razvoja sadnica hrasta lužnjaka i hrasta kitnjaka na prostoru gdje do sada nije bilo uobičajeno saditi navedene vrste, iako za to postoje ekološko gospodarski uvjeti. Istraživanja ukazuju kako je broj biljaka nakon 5 godina izmjere smanjen je za 14%. Kod hrasta lužnjaka smanjen je za 4 do 8%, a kod hrasta kitnjaka za 17 do 22%. Visine i prsni promjeri stabala u štitnicima značajno su veći bez obzira na vrstu drveća. Visine i prsni promjeri hrasta lužnjaka značajno su veće od hrasta kitnjaka. Nije utvrđena povezanost između visina stabala i prisutnosti pepelnice.The research was carried out in the lowland region at a distance of about 3 km from the Drava River at an altitude of 190 m, in an area where mostly spruce, white pine and black locust are planted, although the habitat is suitable for planting and growing oak. Considering the changed ecological and climatological conditions, an experimental plot of 2.00 ha was established. Three-year-old (2 + 1) seedlings of pedunculate oak (Quercus robur) and sessile oak (Quercus petraea) were planted on the plot according to two different methods. The first group was planted at a distance of 3 x 3 m in polypropylene shelters. The second group was planted at a distance of 2 x 2 m in the regular way (without the shelters). The entire area was divided into 24 plots of approximately the same size. Each plot contained only one tree species. The arrangement of species alternated between the plots. A randomized block design was used, with 4 blocks and 3 replicates. Tree heights were measured for 5 consecutive years not during the growing season. Breast height diameters were measured at the end of the observed period. The impact and intensity of powdery mildew has been observed for three years during the summer months. The aim of the research is to study the growth and development of pedunculate oak and sessile oak seedlings in an area where these species were not commonly grown, although there are adequate ecological and economic conditions. After 5 years of measurement, the number of plants was reduced by 14%. In pedunculate oak the number of trees was reduced by 4 to 8%, and in sessile oak by 17 to 22%. The height and breast height diameters of the trees grown within the shelters were significantly higher regardless of the tree species. The height and breast height diameter of pedunculate oak trees was significantly larger than of sessile oak trees. No correlation was found between tree height and the presence of powdery mildew

Past, Present and Future of Application of Remote Sensing Methods in Croatian Forest Inventory

Zadatak inventure šuma je kvalitetno prikupljanje informacija, što predstavlja temelj za donošenje pravilnih odluka u gospodarenju šumama. Uz uobičajene terestričke načine prikupljanja podataka, podaci o šumama sve se više prikupljaju i metodama daljinskih istraživanja, čijom se primjenom smanjuje opseg terenskog rada te otvara mogućnost uštede vremena i novca. Cilj rada je dati pregled dosadašnjih istraživanja te mogućnosti primjene metoda daljinskih istraživanja u inventuri šuma u Hrvatskoj. Dosadašnja istraživanja prikazana u radu dat će uvid u sadašnje stanje i ulogu daljinskih istraživanja u inventuri šuma u Hrvatskoj, a zajedno s novim spoznajama mogu poslužiti kao smjernice za buduća istraživanja i primjenu novih metoda daljinskih istraživanja u inventuri šuma.Making correct decision in forest management is based on the quality of the collected information. Collection information from forests is the main task of the forest inventory. Due to the rapid development of technology, in the second half of the 20th century, there have been major changes in the way of data collection, particularly in developed countries. In addition to conventional terrestrial methods of data collection, data on forests is increasingly being collected with remote sensing methods. Using remote sensing methods leads to reducing the scope of the fieldwork, and opens the possibility of saving time and money. In this paper was given the review of previous research and results of application of remote sensing methods in Croatian forest inventory. Previous researches presented in this paper will give insight into the current status and role of remote sensing in Croatian forest inventory, and along with some new findings may serve as guidelines for future research and application of new methods of remote sensing in forest inventory. Various researches about applicability of remote sensing methods in forest inventory operations, primarily on aerial photographs and more recently on satellite images, were conducted in Croatia in the last 30 and more years. In all previous studies of forest damage assessments with photointerpretation on CIR aerial photographs it was proved that this method is to be equally in comparison with terrestrial methods regarding to accuracy, and much more efficient regarding to achieved speed and objectivity. Methodology suitable for operational use in inventory of forest damage was made. Periodic inventories of forest health with using remote sensing methods enable easy monitoring of changes of forest between two inventories, identification of new foci of dying trees or other damage, which is especially important in today’s changed and altered environmental conditions. Forest management inventory requires information of greater accuracy. Therefore, aerial photographs of higher spatial resolution have more important applications in relation to satellite imagery in forest management inventory. Some researches of using aerial photographs for photogrammetric measurements of stands parameters shown in this paper gave good results. Despite the above, the application of remote sensing methods in practical forest inventory has not been sufficiently utilized. Development of digital photogrammetry and ‘new’ remote sensing methods and systems such as lidar, and improving existing ones, increasing the possibilities and scope of remote sensing methods. Therefore is necessary to continuously monitor the latest developments and explore new additional possibility of their application in forest inventory

Review of nonmarket forest goods and services evaluation methods

Background and Purpose: Natural resource systems that are commercially exploitable, such as forests, are valued by using many different factors. Policy makers and other decision makers must choose between scenarios in which there can be clear market values with easy to document influences on economy or scenarios in which the value is placed on difficult to document factors, such as the importance of natural systems, forest services without market values, and the benefits to human wellbeing. Several methods are described in this paper for documenting the non-market values that forest goods and services provide. We discuss different methods and assessment tools that provide different types of information, quantitative and qualitative, with respective strengths and weaknesses from varied scientific and decision-support perspective. In an attempt to provide scientists with different views and ideas, as well as planners and managers with a general appreciation of methods and their application, we have included selected examples that influence policy and/or management practices. Material and Methods: Most of the material has been developed based on a number of basic text books describing evaluation methods from the perspective of development and grounded in economical theory with a wide range of application. The second part has been developed from a list of references dealing with application in European countries and enriched with details and examples from documents based on seventeen country reports. The structure of those country reports was predefined, discussed, harmonized and completed by a group of scientists and professionals involved in COST action E-33, »Forest for recreation and tourism.« Evaluation methods related to forest goods and services were described from theoretical and practical viewpoints with emphasis on their applicability to a specific type of research. Results and Conclusion: Nonmarket values of forest goods and services can be estimated in a number of different ways. The methods can be divided into two basic categories: first, based on market prices, and second, based on non-market evaluation. Our focus is on the second strategy where the market prices are not known. Further division of this method goes in two broad categories according to the nature of the data generated for modelling and estimation: (a) »stated preference methods« where individuals’ preferences are not observed but rather stated, and (b) »revealed preference methods« where we can observe people acting in real-world settings where people live with the consequences of their choices.The most widely used method for valuing natural resources is the contingent valuation (CV) method. Choice experiments (CE) and hedonic pricing (HP) methods have been included in far fewer empirical studies, but the application of these methods has passed the demonstration stage. We also discuss the newly developed methods of benefit transfer and meta-analysis which use values, functions, and other descriptions from other studies to evaluate natural resources

Climate and relief properties influence crown condition of common beech (Fagus sylvatica L.) on the Medvednica massif

Background and Purpose: Common beech is a dominant broadleaved tree species in European forests, and also on the Medvednica massif. Since climate is a decisive factor in the development of a certain type of vegetation, it might have an equally important role in its survival. The influence of relief properties on the crown condition of common beech (Fagus sylvatica L.) can also be significant, since beech stands on Medvednica vary in their elevation and exposition. Materials and Methods: Twelve common beech research plots, with complete defoliation data sets in the period 2004–2006 were chosen to represent the variety of environmental conditions present on the Medvednica massif in the western Pannonian region of Croatia. Climate parameters used in the model included annual precipitation (AP), precipitation in the vegetation period (VP), mean annual air temperature (AT), and mean air temperature in the vegetation period (VT). The elevation (EL) of the experimental plots and data from the meteorological station of Puntijarka were used to obtain an estimate of the AT, VT, AP and VP on each research plot. Results: The share of moderately to severely damaged trees (crown defoliation over 25%) was highest in 2004, an expected result of the 2003 drought. This value was significantly higher than in the following two years. The determining climate parameter explaining the changes in defoliation was VP, and the most decisive relief parameter was EL. Defoliation was higher with low VP and higher EL. D was higher predominantly on southern expositions. Conclusions: Climate and relief properties were found to significantly influence the crown condition of beech trees. Although there is a significant positive trend of temperature change on Medvednica, in the period 2004–2006 precipitation in the vegetation period had the dominant effect on the crown condition

Forest biomass and sequestered carbon estimation according to main tree components on the forest stand scale

Background and Purpose: The estimation of forest woody biomass has a significant role in forestry due to several reasons. One of the reasons is that good woody biomass estimation is important for the planning of forest woody assortments production, for main commercial roundwood assortment and for assortments like »waste wood« or »recovered wood« as a potential for electricity (heat) generation (firewood, wood bricks, wood pellets etc.). Economic and political meaning of woody biomass estimation is important to know forest biomass resources in the country and present these facts to international institutions or in treaties as needed. The estimation is also important for strategic planning of the use of renewable energy sources from woody biomass. On the other hand, estimation of the carbon content in forest woody biomass has importance in global climatemitigation policy and processes (Kyoto- and post-Kyoto period). The purpose of this paper is to present methodology applied for estimation of forest woody biomass and its carbon content according to main tree components, on the forest stand scale. Material and Methods: As research area, two representative Croatian forest communities/stands were selected. The one represents flooded lowland pedunculate oak forest of Pokupski Basin, and the other represents mountain fir-beech forest of the Gorski Kotar region. Emphasis in the paper is on themethodology which was developed for the purpose of research. The methods applied in this study consist of: a) dendrometrical measurements on selected forest stands (research sites), b) sampling of main tree components and sample analyses in laboratory, and c) calculation of forest woody biomass and its carbon content according to main tree components. Results: General result of the laboratory analyses of the samples of main tree componets is that the carbon content in biomass was around 50,0% of the dry matter of a component. In line with volume allocation of main tree components are the biomass of tree components and the content of carbon sequestered in these components. Stem had the largest share in total tree biomass while foliage or needle biomass had the smallest share. The shares of main tree components in total biomass of the tree depend on morphology each of tree species. Conclusion: This research was a pilot and pioneering research of forest biomass in Croatian forestry, and it should be continued to acquire better knowledge of relations in forest woody biomass in main forest communities in Croatia

Review of nonmarket forest goods and services evaluation methods

Background and Purpose: Natural resource systems that are commercially exploitable, such as forests, are valued by using many different factors. Policy makers and other decision makers must choose between scenarios in which there can be clear market values with easy to document influences on economy or scenarios in which the value is placed on difficult to document factors, such as the importance of natural systems, forest services without market values, and the benefits to human wellbeing. Several methods are described in this paper for documenting the non-market values that forest goods and services provide. We discuss different methods and assessment tools that provide different types of information, quantitative and qualitative, with respective strengths and weaknesses from varied scientific and decision-support perspective. In an attempt to provide scientists with different views and ideas, as well as planners and managers with a general appreciation of methods and their application, we have included selected examples that influence policy and/or management practices. Material and Methods: Most of the material has been developed based on a number of basic text books describing evaluation methods from the perspective of development and grounded in economical theory with a wide range of application. The second part has been developed from a list of references dealing with application in European countries and enriched with details and examples from documents based on seventeen country reports. The structure of those country reports was predefined, discussed, harmonized and completed by a group of scientists and professionals involved in COST action E-33, »Forest for recreation and tourism.« Evaluation methods related to forest goods and services were described from theoretical and practical viewpoints with emphasis on their applicability to a specific type of research. Results and Conclusion: Nonmarket values of forest goods and services can be estimated in a number of different ways. The methods can be divided into two basic categories: first, based on market prices, and second, based on non-market evaluation. Our focus is on the second strategy where the market prices are not known. Further division of this method goes in two broad categories according to the nature of the data generated for modelling and estimation: (a) »stated preference methods« where individuals’ preferences are not observed but rather stated, and (b) »revealed preference methods« where we can observe people acting in real-world settings where people live with the consequences of their choices.The most widely used method for valuing natural resources is the contingent valuation (CV) method. Choice experiments (CE) and hedonic pricing (HP) methods have been included in far fewer empirical studies, but the application of these methods has passed the demonstration stage. We also discuss the newly developed methods of benefit transfer and meta-analysis which use values, functions, and other descriptions from other studies to evaluate natural resources

Estimation of the stands’ arithmetic mean diameter using manual method of digital photogrammetry

Background and Purpose: The development of digital photogrammetry during the last twenty years has reopened the question of the possibility of its application in forest inventory. The focus of this paper is to research the potential of the manual method of digital photogrammetry for the estimation of diameter at breast height (DBH) at stand level. Material and Methods: The results (stands\u27 arithmetic mean diameter) obtained by classical terrestrial measurement and photogrammetric measurement were compared for the selected part of the \u27Donja Kup~ina – Pisarovina\u27 management unit. Photogrammetric measurements of tree variables (height, crown diameter), necessary for DBH estimation, were carried out in the stereomodels of colour infrared digital images of 30 cmand 10 cm spatial resolution, i.e. ground sample distance (GSD) using digital photogrammetric workstation. Results: The repeated measures ANOVA testing determined statistically significant differences between the results obtained by terrestrial and photogrammetric measurements (GSD 10 cm and GSD 30 cm) of the arithmetic mean DBH of subcompartments. Furthermore, the testing determined no statistically significant differences between the \u27trends\u27 of estimating DBH by different methods. In other words, a \u27pattern of constant overestimation\u27 of DBH, taken by the photogrammetric measurement in relation to terrestrial measurement, was noted for all subcompartments. The value of overestimation was lesser in case of aerial images of GSD 10 cm(1.45–3.90 cm) and greater in case of images of GSD 30 cm (2.55–5.29 cm). Conclusions: Considering the obtained results, it can be concluded that the method used in this research may find its practical application primarily in forests of less intensive management (protective forests, forests with special purposes, privately-owned forests), where a compromise between the data collection costs and utilization value is necessary

Digital Photogrammetry – State of the Art and Potential for Application in Forest Management in Croatia

Background and purpose: The main goal of this paper is to inform forestry community about the latest developments in digital photogrammetry, as well as to present its possible application in forest management. For this purpose, the current state of technological development of the main tools of digital photogrammetry (digital aerophotogrammetric cameras and digital photogrammetric workstations) has been presented. Furthermore, two adjusted methods of manual digital photogrammetry for application in forest management, namely: method for strata delineation (i.e. creation of forest management division), and method for measuring stand structure elements have been developed and presented here. Material and methods: Research was carried out on the selected part of multi-aged, privately owned forest of \u27\u27Donja Kupčina - Pisarovina\u27\u27 management unit which includes 6 compartments and 24 subcompartments and covers total area of 480 ha. After conducted aerial survey of research area, acquired digital images were processed, and digital terrain model and digital elevation model were derived. Digital aerial images of ground sample distance of 10 cm, topographical maps, digital terrain model and digital elevation model, as well as the digital photogrammetric workstations with appropriate software (PHOTOMOD, Global Mapper) were used for developing methods for strata delineation and stand structure elements estimation. Developments of both methods were carried out in the stereomodel of colour infrared digital aerial images in PHOTOMOD StereoDraw module. Additional data processing was conducted in ArcGIS 9.1 (for strata delineation) and in Global Mapper (for stand structure elements estimation) software. Discussion and conclusions: This research has showed that PHOTOMOD Lite and Global Mapper software packages in combination with the used materials (digital aerial images, digital elevation model) and digital photogrammetric workstation completely satisfy the needs for strata delineation and stand structure measurements. The PHOTOMOD software enables simple creation of projects of digital images, easy manipulation of multiple digital images, and many other features that facilitate photogrammetric measurement and photo-interpretation, but its free version PHOTOMOD Lite has limited capabilities in terms of number of images and quantity of vector data that can be processed. If digital images of high spatial resolution are used (e.g. 30 cm or better), as was the case in this research, stereo-effect experienced by the operator and the quality of photo-interpretation are very good. That enables clear determination of vegetation types and as well as single tree species, more accurate pinpointing of tree tops and more accurate delineation of tree crowns. As long as automatic procedures are not available, digital photogrammetry has to rely on manual methods. Allometric relation between variables measured with photogrammetric method and desired variables need to be developed. An attempt to address this issue, at least in part, is made within the ongoing project \u27Application of digital photogrammetry in practical forest management\u27

Does "FOPER" Has Its Own Forest?

Background and purpose: Nowadays, when the environmental protection is increasingly gaining in importance, initiation such as conversion of productive forest with primary economic functions into forests with special purpose should be positively welcomed. FOPER forest near Varaždin is an example of this kind of conversion. FOPER Forest is one of the outcomes of FOPER Project which was established on the area of South East Europe. FOPER Forest is located on the area of 3.60 ha of the Management Unit "Zelendvor". On one half of that area Research forest was planted, while on the other half Memorial Park will be planted in spring 2013. Overall aims of FOPER Forest is to acquire habits of people who are living in urban areas to visit green areas; to raise their environmental awareness and to strengthen cooperation in education and research; but even more important is strengthening cooperation and friendship in South East Europe (SEE). Specific aim of FOPER Forest is visitors’ education about vegetation of FOPER Project countries in Memorial park and conducting researches in Research part. Material and methods: Two main methods were used to gather the material on FOPER Project and on FOPER Forest: (I) published literature was reviewed, (II) the Internet and relevant web sites provided access to other information. Discussion and conclusion: Good promotions of FOPER Forest can attract potential tourists and visitors and raise not only their environmental awareness, but also their awareness of importance of forestry as profession. They could see that forestry is not narrow profession which deals only with management of forests, but a complex scientific profession, which deals with variety of different fields. FOPER Forest is the great example of the overall guiding principle of FOPER Project which is „learning by doing”